This article looks at the two major systems for adding data to posts in WordPress: custom taxonomies and custom fields. Since some needs can reasonably by solved by either custom fields or custom taxonomies, we’ll use a practical example—a movie review site—to help define overall principles for when it’s best to use each tool. The Two Crucial Types of Post Data in WordPressIn WordPress, you need to think about two types of data that you can attach to your posts: taxonomies and “fields.” Since we’re discussing creating custom data, I’ll mostly be referring to “custom taxonomies” and “custom fields.”What Custom Taxonomies Are To understand custom taxonomies well, it’s most helpful to think about WordPress’s built in taxonomies: Post Tags and Post Categories. For both, they’re a systematic ways to organize and think about your data. The biggest distinguishing feature of them, though, is that they’re not unique data. For both tags and categories, you’re using the same word or phrase on multiple different posts. You’re essentially attaching an independent data point — that tag or category — to your post. It’s important to realize that custom taxonomies like tags hold their own data, and can change independently of the posts they are attached to. For example, I may have once used the tag “wapo” on a site, because I has a post that referred to The Washington Post. Now I want to be more clear, so I want that tag (and the 79 posts that have it) to look like… [Read full story]